SKYHOOK-203: [Doc] Fix the benchmarking.md guide

cpp/src/arrow/adapters/arrow-rados-cls/docs/benchmarking.md

@@ -17,7 +17,7 @@
   under the License.
 -->
 
-# Setting up and benchmarking SkyhookDM
+# Benchmarking SkyhookDM
 
 1. Download the required scripts and make them executable.
 
@@ -30,7 +30,7 @@ wget https://raw.githubusercontent.com/uccross/skyhookdm-arrow/arrow-master/cpp/
 2. Execute deploy_ceph script to deploy a Ceph cluster on a set of nodes and to mount CephFS on the client/admin node. On the client node, execute:
 
 ```bash
-./deploy_ceph.sh mon1,mon2,mon3 osd1,osd2,osd3 mds1 mgr1
+./deploy_ceph.sh mon1,mon2,mon3 osd1,osd2,osd3 mds1 mgr1 /dev/sdb 3
 ```
 where mon1, mon2, osd1, etc. are the internal hostnames of the nodes.
 
@@ -49,20 +49,33 @@ apt install git-lfs
 git clone https://github.com/jayjeetc/datasets
 cd datasets/
 git lfs pull
+cd ..
 ```
 
 5. Create and write a sample dataset to the CephFS mount by replicating the 128MB Parquet file downloaded in the previous step:
 
 ```bash
-./deploy_data.sh datasets/128MB.parquet /mnt/cephfs/dataset 100 134217728
+./deploy_data.sh [source file] [destination dir] [no. of copies] [stripe unit]
 ```
 
-This will write 100 of ~128MB Parquet files to /mnt/cephfs/dataset using a CephFS stripe size of 128MB.
+For example,
+
+```bash
+./deploy_data.sh datasets/128MB.parquet /mnt/cephfs/dataset 240 134217728
+```
+
+This will write 240 of ~128MB Parquet files to /mnt/cephfs/dataset using a CephFS stripe size of 128MB.
 
 6. Optionally, you can also deploy Prometheus and Grafana for monitoring the cluster by following [this](https://github.com/JayjeetAtGithub/prometheus-on-baremetal#readme) guide.
 
-7. The benchmark script ([bench.py](../scripts/bench.py)) can be used to generate benchmarks in the following syntax:
+7. Run [this](../scripts/bench.py) benchmark script to get some initial benchmarks for SkyhookDM performance while using different row selectivities.
+
+```bash
+wget https://raw.githubusercontent.com/uccross/skyhookdm-arrow/arrow-master/cpp/src/arrow/adapters/arrow-rados-cls/scripts/bench.py
+python3 bench.py [format(pq/rpq)] [iterations] [file:///path/to/dataset] [workers] [result file]
+```
 
+For example,
 ```bash
-./bench.py <format(pq/rpq)> <iterations> <dataset> <workers> <file>
+python3 bench.py rpq 10 file:///mnt/cephfs/dataset 16 result.json
 ```